ID   CFAB_PIG                Reviewed;         151 AA.
AC   Q03710;
DT   15-DEC-1998, integrated into UniProtKB/Swiss-Prot.
DT   01-NOV-1996, sequence version 1.
DT   03-AUG-2022, entry version 107.
DE   RecName: Full=Complement factor B;
DE            EC=3.4.21.47;
DE   AltName: Full=C3/C5 convertase;
DE   AltName: Full=Properdin factor B;
DE   Flags: Fragment;
GN   Name=CFB; Synonyms=BF;
OS   Sus scrofa (Pig).
OC   Eukaryota; Metazoa; Chordata; Craniata; Vertebrata; Euteleostomi; Mammalia;
OC   Eutheria; Laurasiatheria; Artiodactyla; Suina; Suidae; Sus.
OX   NCBI_TaxID=9823;
RN   [1]
RP   NUCLEOTIDE SEQUENCE [GENOMIC DNA].
RX   PubMed=1680099; DOI=10.1007/bf00205823;
RA   Peelman L.J., van de Weghe A.R., Coppieters W.R., van Zeveren A.J.,
RA   Bouquet Y.H.;
RT   "Cloning and sequencing of the porcine complement factor B.";
RL   Immunogenetics 34:192-195(1991).
CC   -!- FUNCTION: Factor B which is part of the alternate pathway of the
CC       complement system is cleaved by factor D into 2 fragments: Ba and Bb.
CC       Bb, a serine protease, then combines with complement factor 3b to
CC       generate the C3 or C5 convertase.
CC   -!- CATALYTIC ACTIVITY:
CC       Reaction=Cleavage of Arg-|-Ser bond in complement component C3 alpha-
CC         chain to yield C3a and C3b, and Arg-|-Xaa bond in complement
CC         component C5 alpha-chain to yield C5a and C5b.; EC=3.4.21.47;
CC   -!- SUBUNIT: Monomer (By similarity). Part of the C3-convertase enzyme
CC       complex comprised of Complement C3 beta chain (C3b) and Complement
CC       factor B Bb fragment (Bb) and CFP (By similarity). Interacts to C3b;
CC       this interaction is dependent on the presence of Mg2+ (By similarity).
CC       Interacts to CFP; this interaction contributes to the stabilization of
CC       the active C3-convertase enzyme complex (By similarity).
CC       {ECO:0000250|UniProtKB:P00751}.
CC   -!- SUBCELLULAR LOCATION: Secreted.
CC   -!- SIMILARITY: Belongs to the peptidase S1 family. {ECO:0000255|PROSITE-
CC       ProRule:PRU00274}.
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DR   EMBL; M59240; AAA31021.1; -; Genomic_DNA.
DR   AlphaFoldDB; Q03710; -.
DR   SMR; Q03710; -.
DR   STRING; 9823.ENSSSCP00000001522; -.
DR   MEROPS; S01.196; -.
DR   PaxDb; Q03710; -.
DR   PeptideAtlas; Q03710; -.
DR   PRIDE; Q03710; -.
DR   eggNOG; KOG3627; Eukaryota.
DR   InParanoid; Q03710; -.
DR   Proteomes; UP000008227; Unplaced.
DR   Proteomes; UP000314985; Unplaced.
DR   GO; GO:0005601; C:classical-complement-pathway C3/C5 convertase complex; IBA:GO_Central.
DR   GO; GO:0004252; F:serine-type endopeptidase activity; IEA:UniProtKB-EC.
DR   GO; GO:0006956; P:complement activation; IBA:GO_Central.
DR   GO; GO:0006957; P:complement activation, alternative pathway; IEA:UniProtKB-KW.
DR   GO; GO:0006508; P:proteolysis; IEA:UniProtKB-KW.
DR   GO; GO:0009617; P:response to bacterium; IBA:GO_Central.
DR   CDD; cd00033; CCP; 2.
DR   InterPro; IPR011360; Compl_C2_B.
DR   InterPro; IPR028341; Complement_B.
DR   InterPro; IPR035976; Sushi/SCR/CCP_sf.
DR   InterPro; IPR000436; Sushi_SCR_CCP_dom.
DR   PANTHER; PTHR46393; PTHR46393; 1.
DR   PANTHER; PTHR46393:SF1; PTHR46393:SF1; 1.
DR   Pfam; PF00084; Sushi; 2.
DR   SMART; SM00032; CCP; 2.
DR   SUPFAM; SSF57535; SSF57535; 2.
DR   PROSITE; PS50923; SUSHI; 2.
PE   3: Inferred from homology;
KW   Complement alternate pathway; Disulfide bond; Glycoprotein; Hydrolase;
KW   Immunity; Innate immunity; Protease; Reference proteome; Repeat; Secreted;
KW   Serine protease; Sushi.
FT   CHAIN           <1..>151
FT                   /note="Complement factor B"
FT                   /id="PRO_0000088663"
FT   DOMAIN          1..61
FT                   /note="Sushi 2"
FT                   /evidence="ECO:0000255|PROSITE-ProRule:PRU00302"
FT   DOMAIN          64..121
FT                   /note="Sushi 3"
FT                   /evidence="ECO:0000255|PROSITE-ProRule:PRU00302"
FT   CARBOHYD        23
FT                   /note="N-linked (GlcNAc...) asparagine"
FT                   /evidence="ECO:0000255"
FT   CARBOHYD        43
FT                   /note="N-linked (GlcNAc...) asparagine"
FT                   /evidence="ECO:0000255"
FT   DISULFID        4..46
FT                   /evidence="ECO:0000250"
FT   DISULFID        32..59
FT                   /evidence="ECO:0000250"
FT   DISULFID        66..106
FT                   /evidence="ECO:0000250"
FT   DISULFID        92..119
FT                   /evidence="ECO:0000250"
FT   NON_TER         1
FT   NON_TER         151
SQ   SEQUENCE   151 AA;  16765 MW;  BD247E75047E517F CRC64;
     AIRCPRPHDF ENGEYWPRAP YYNLSDEISF HCYDGYTLRG SANRTCQVTG RWDGQTAICD
     DGAGYCPNPG IPIGTRKVGT QYRLEDSVTY YCTRGLTLRG SQRRTCQEGG SWSGTEPSCQ
     DSFMYDTPAE VAEAFLSSLT ETIEGVDAED G